What is a Y plan heating system & how does it work? In this guide we explain it all, as well as potential limitations.
If you’ve heard of heating systems described by letters, such as S, W or Y, you might be wondering what these mean.
Ultimately, these letters describe the components and arrangement of a heating system.
Just as you can categorize boilers based on their fuel type (e.g., oil, gas, or electricity) and their scale and broad set-up (e.g., combi or system), you can categorize boilers with letters to fit the aforementioned description.
What’s more, is that this form of categorization covers the entire heating system and not simply the boiler itself.
But what about Y plan heating systems in particular?
What is a Y Plan Heating System?
A Y Plan features one three-port valve that is used to supply the hot water or/and central heating.
Unsurprisingly, this valve is shaped like a Y (at least when viewed as a schematic layout of the pipework), owing to the name of this heating system design.
A common reason why a household may have a Y Plan heating system is that they do not have sufficient space for an S plan design.
Ultimately, an S plan heating system comes with more components.
Therefore, a Y plan (as mentioned) takes up less space. It’s also easier to install as a result. In many cases, you’ll find a Y plan heating system in older households.
Y Plan Heating System Diagram:
In fact, they tend to still be usable if only small repairs or replacement jobs are required to keep them in healthy working order.
In more detail, here’s how a three-port valve functions:
The motorised valve comes with two internal micro switches.
The first switch moves once the valve reaches the middle position, while the second switch moves over once the valve is in the Heating Only position.
As power goes through the Heating Only wire (the white wire), 230 volts of electricity reaches the motor. This causes the motor to turn until reaching the middle position. This causes the first switch to move position with the 230 volts of electricity no longer being received.
As a result, the power travelling through the white wire will continue but only reach the second switch.
The voltage travels via a diode where it is converted into DC prior to reaching the motor.
Electricity will also be travelling to the motor via the orange wire. However, it makes its way through two resistors before it lands in the motor.
The DC voltage (along with reduced AC volts) can maintain the motor in the middle position. However, it won’t cause the valve to move beyond this.
If the system can easily meet your hot water demand (or no demand exists), 230 volts of electricity will travel along the grey wire, to turn off the hot water.
Once this happens, the grey wire powers the motor (again with 230 volts) once switch one has moved position. This occurs once the valve is in the middle position. Ultimately, this all means that the valve can now reposition to the Heating Only position.
The valve will stay like this since there is a continuous supply of 230 volts via the grey wire.
This remains the case before hot water is next demanded.
Pros and Cons of a Y Plan Heating System
So, what are the advantages and disadvantages of using this type of heating plan over other system designs (e.g., S plan or M plan)?
Pros:
Generally, lower fuel costs than other system designs.
Comes with the timed operation of heating components.
Closed temperature control of the heating system and hot water generation.
Cons:
May dilute and limit water flow
Y Plan Heating System Common Issues
Issues that you may commonly find with a Y plan heating system include:
A frequently recurring issue with this style of heating system is when a boiler runs and heats up your radiators when it’s not directed to. If the voltage travelling through the motorised valve (which connects the grey and orange wires) has limited voltage, it can lead to the aforementioned problem. This can generally be solved by having an electrician install a capacitor or wiring suppressor in this location. Do not attempt such electrical works DIY.
It’s possible that a valve could become stuck, particularly after being in a single position all summer long. Attempts of the valve to move can result in the head burning out. Ultimately, this will mean you’ll need to have the three-port valve replaced.
If you need to have a three-port valve replaced, it will probably cost somewhere in the region of £80 to £120.
However, this would depend on factors such as where you live and the exact cost of the replacement part.
Should I Replace my Boiler/Heating System?
If your boiler is particularly old or otherwise beyond economical repair (BER), it might be best to have it replaced.
Here are a few examples of a boiler being BER:
The repair cost is around 60% or more than the price of having a new boiler installed.
You have an expensive part which needs replacing, such as a PCB.
Your boiler is around fifteen years old.
At this stage, you find your boiler is breaking down too often.
You’ve noticed that issues continue to recur (after a relatively short period of time) with your boiler even after they are initially fixed.
Of course, in the current economic climate, a boiler replacement would be unthinkable for most households right now, at least if dealing with an upfront cost.
The good news is that it’s possible to purchase a boiler on finance (i.e., buy now and pay later).
As for your heating system as a whole, this will depend on how well it is functioning.
Likewise, if it is beyond economical repair, it’s best to have it replaced.
If you’re not sure whether or not this is the case (whether with your boiler or heating system as a whole), you can always contact a heating engineer to come out and make an assessment.
That way, you’ll get an idea of what the smartest moves are moving forward.
Of course, just as with a boiler, you could look into purchasing an entirely new heating system on finance or even taking out a loan.
Another possibility is paying by credit card, but you’d want to proceed with great caution if considering this route.
Purchasing, say, a boiler on finance (especially with low or no interest) would be a safer option overall.
